It has long been recognized in the art that surfactants are highly desirable, in fact, almost essential, to effective cleaning performance by a cleaning composition. However, it has also been recognized that there is room for improvement in surfactant-based cleaning products.
Applicant is aware of a wide variety of surfactant-based cleaning compositions which contain tertiary butanol, used primarily for its physical ability to solubilize the detergent composition itself or as a solvent. Several representative references follow. U.S. Pat. No. 3,966,649, issued to Cheng on June 29, 1976, discloses the use of tertiary butanol in a heavy duty liquid laundry detergent composition to improve the stability of the composition and prevent gelling. U.S. Pat. No. 3,997,481, issued to Cheng on Dec. 14, 1976, provides a similar teaching. U.S. Pat. No. 3,463,735, issued to Stonebraker et al. on Aug. 26, 1969, discloses a hard-surface and glass cleaner which contains, among other things, 0.5% to 5% tertiary butanol and 0.05% to 0.5% of a surfactant in aqueous solution. U.S. Pat. No. 3,248,336, issued to Blumbergs on Apr. 26, 1966, discloses that tertiary butanol may be used to stabilize aqueous peroxybenzoic acid laundry bleaches. The specification teaches that such bleaches may be used in conjunction with the usual laundry detergents to wash and bleach clothes simultaneously.
The applicant has discovered one reference which teaches that a tertiary alcohol such as tertiary butanol may be used to treat a crude sulfonated or sulfated surfactant to remove inorganic salts from the surfactant. The surfactant is recovered from the treatment liquor after the operation is completed, however, so the combination of a tertiary alcohol and a surfactant is not taught to have any utility per se.
Applicant is aware of a reference which teaches the use of a tertiary alcohol to solubilize polyisopropylene gum, which is used as an ingredient of the disclosed composition. That patent is U.S. Pat. No. 4,100,093, issued to Rialdi on July 11, 1978.
U.S. Pat. No. 3,829,387, issued to Wise et al. on Aug. 13, 1974, discloses the optional use of 2-methyl-2, 4-pentanediol in an oven cleaning composition which also may include a surfactant. It will be recognized that this compound is not a tertiary alcohol, as defined hereinafter, because it contains a secondary alcohol moiety.
Finally, the following U.S. Patents are believed to be less relevant, and disclose the use of primary or secondary alcohols, or ones undifferentiated by degree, in detergent compositions. U.S. Pat. No. 3,679,609, issued to Castner on July 25, 1962, discloses a detergent concentrate containing lower alcohols and surfactants U.S. Pat. No. 3,741,902, issued to Barrett on June 26, 1973, discloses the use of butanols as carriers for a nonionic surfactant in an anhydrous mixture. U.S. Pat. No. 3,746,649, issued to Barrett on July 17, 1973, discloses the use of butanols as vehicles for an enzyme composition. U.S. Pat. No. 3,776,851, issued to Cheng on Dec. 4, 1973, teaches the use of tetrahydroxysuccinic acid--a quadrifunctional secondary alcohol--as a builder in a laundry detergent. U.S. Pat. No. 3,813,343, issued to Mukai on May 28, 1974, teaches heavy duty cleaning compositions containing specified primary and secondary alcohols. U.S. Pat. No. 3,855,142, issued to Pader et al. on Dec. 17, 1974, teaches an enzyme containing denture soaking composition which utilizes an isopropanol vehicle.
It will be apparent from the cited references that it is not new to use alcohols per se in a surfactant based cleaning composition, and it is not new to use tertiary butanol in a cleaning composition which is surfactant based. However, it is apparent that the utility of tertiary alcohols with more than 4 carbon atoms in their molecular structure as an adjunct to surfactant-based cleaning compositions has never been appreciated by the art.